142 THE ELECTRIC TELEGRAPH. 



termediate stations connect up for translation, the signals 

 may be passed through the whole with no interference on 

 the part of the employes. When the printing beam is 

 drawn from the upper contact 2, to the lower one B, 

 by the galvanic current, a certain interval is necessary, 

 and this interval could be subtracted from the time the 

 armature is actually held down, and consequently from the 

 lengths of signals on the paper. The printing beam would 

 therefore actually be attracted for a shorter space of time 

 than the key is held down at the sending station. The 

 diminution would be repeated at each following station, so 

 that, in fine, if there were several stations translating, the 

 primary signals would have to be transmitted very slowly, 

 in order that they might be legibly received at the terminal 

 instrument. This is remedied, in an ingenious way, by Siemens 

 and Halske's translating spring, which is situate under the 

 printing beam, and immediately above the contact point 3. 

 As soon as the beam commences its downward motion, 

 following the attraction of the armature, the spring touches 

 the contact point 3 ; and when the beam leaves the point, the 

 spring still presses upon it for a time, and only separates 

 from it at the last moment, so that the manipulator need 

 not give any special attention to the length of his signals 

 in working the key, as they will be transmitted exactly as 

 he sends them, provided the line be properly discharged. 



87. Complete Submarine Board. For use on submarine 

 lines, Siemens and Halske have had the polarised ink recorder, 

 polarised relay, submarine key, and other apparatus, set up 

 on slate slabs, the connections of a permanent character 

 between the various parts being made underneath the board. 

 The binding screws of the local circuit are marked with italic, 

 and those of the line circuit in Arabic numerals and letters. 



Fig. 80 gives a theoretical plan of the connections of two 

 slabs at an intermediate or translating station, and Fig. 81 

 the arrangement of the various parts of the apparatus in one 

 of the slabs. B B (Fig. 81) are the galvanoscopes, c the 

 translation commutator, D the submarine key, F the current 

 commutator, G the relay, H the printing instrument, and M 



